The NEXUS project explored how advanced technologies and higher levels of metro automation, including fully automated operations (i.e., GoA4), could support the future of metro services in Genoa and Sofia. It examined the existing levels of automation in both cities and gathered insights from metro operators through a survey. This helped the project better understand the opportunities, practical challenges and needs associated with moving towards greater automation. As the number and detail of survey responses varied, the findings should be considered indicative rather than precise estimates for each individual metro system.
The project assessed how automation could improve metro operations and create benefits for passengers, operators and the wider city. The findings suggest that more automated services could improve reliability, reduce waiting times and help metro systems carry more passengers. Improved passenger-flow and crowding management could also make journeys more comfortable and accessible. By making public transport more attractive, these improvements could encourage more people to choose the metro instead of travelling by private car.
A shift towards public transport can bring wider benefits beyond the metro itself. Reduced car use could help ease road congestion, lower air pollution and reduce traffic-related accidents, while also saving time for travellers. These broader societal benefits are an important part of understanding the potential value of metro automation. They also highlight that the benefits of GoA4 are not limited to direct financial gains for the operator.
The economic assessment found a positive overall case for both metro systems, with benefit-cost ratios of 1.35 for Genoa and 1.27 for Sofia. These results indicate that the wider benefits considered in the assessment outweigh the costs under the assumptions used. However, the financial assessment also highlighted that additional revenues alone may not be enough to cover the substantial upfront investment required. Therefore, external funding and planning of local needs will be important for any future implementation.
Hence, NEXUS shows that the transition towards advanced metro automation involves much more than introducing new technology. Realising its potential requires a broader perspective that considers passenger experience, environmental and societal impacts, investment costs, reliable evidence and organisational readiness. By bringing these elements together, the project provides insights and practical resources to help metro operators and authorities explore future automation pathways in a structured and informed way.